title: Reversible contraceptive effect of the oviduct plug with nickel-titanium shape memory alloy and silicone rubber in rabbits.
abstract: BACKGROUND
  The aim of this study was to observe the contraceptive effectiveness and reversibility of the oviduct plug with nickel-titanium (Ni-Ti) shape memory alloy and silicone rubber in rabbits.
  
  
  METHODS
  The oviduct plugs with Ni-Ti shape memory alloy and silicone rubber were made as contraceptive devices. The frame of the oviduct plug is made of silicone rubber and Ni-Ti shape memory alloy wire. The central part of the frame resembles a circular cylinder and the amphi-terminal of the frame is like a spigot which is formed with three mounting rings. Thirty-five New Zealand adult female rabbits were randomly divided into three groups. Thirty rabbits in Group 1 were used to test the contraceptive effect of the oviduct plug. Ten rabbits in Group 2 were used to assess the reproductive reversibility of the rabbits; 3 months after the operation, the oviduct plugs were removed from the junction of the uterus and tubes by incision of the abdomen. Another five rabbits (Group 3) served as the control group. In 30 female rabbits (Group 1), the plugs were inserted into the oviducts via a 0.5-cm incision of the uterus by using an inserter that contained the plug, then the female rabbits copulated with male rabbits once a week after the operation for 1 month. The plugs were then taken out from 10 rabbits (Group 2) 3 months after the operation.
  
  
  RESULTS
  Out of 30 cases (Group 1), only one rabbit from Group 1 was pregnant 2 months after the insertion of the plugs due to improper insertion. However, five rabbits in the control group were all pregnant. All 10 rabbits from Group 2 were pregnant 1 month after the plug was removed.
  
  
  CONCLUSIONS
  The oviduct plug with Ni-Ti shape memory alloy and silicone rubber is a new, effective and reversible contraceptive tool.
authors.affiliation: Key Laboratory for Improving Birth Outcome Technique, Shandong Provincial Family Planning Institute of Science and Technology, Shandong 250002, China.
authors.forename: Lei-Guang
authors.initials: LG
authors.lastname: Wang
authors.forename: Yi
authors.initials: Y
authors.lastname: Qiu
authors.forename: Yun-Jing
authors.initials: YJ
authors.lastname: Fan
authors.forename: Xin-Ying
authors.initials: XY
authors.lastname: Li
authors.forename: Xiang-Jun
authors.initials: XJ
authors.lastname: Han
mesh_terms: D000818:Animals; D003267:Contraception / Q000379:methods*; D003274:Contraceptive Devices, Female; D005260:Female; D008297:Male; D009532:Nickel; D010057:Oviducts / Q000601:surgery*; D011247:Pregnancy; D011817:Rabbits; D011897:Random Allocation; D012826:Silicone Elastomers; D014025:Titanium
chemical_list: D012826:Silicone Elastomers; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium